Conventional breeding methods

Mike Lassner (Verdia Inc.) presented examples of the usefulness of directed molecular evolution as an in vitro process that more easily achieves what was traditionally attempted via reproductive crossing and recurrent selection (plant breeding). Proteins may be engineered that have specific desirable characteristics via methods that "evolve" the basic underlying DNA. For example, the outcome can be enzymes with improved kinetic properties that result in enhanced primary production, or proteins that remain operational under extreme conditions. In addition, compositional proteins may be enhanced to provide functional performance that was not achievable via conventional methods. 

Conventional breeding has developed oilseed rape (Brassica napus) cultivars that can accumulate long-chain fatty acids such as C20 1 and C22 l, however the ability to accumulate short-chain fatty acids is limited. Similarly the ability to accumulate industrially useful hydroxy fatty acids and epoxy fatty acids is also limited with conventional breeding methods. Due to its close relationship to the crucifer Arabidopsis and its associated characterised genome, and the relative ease with which genes can be inserted into Brassica species, oilseed rape is seen as a key target species for genetic manipulation. 

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